题目AcWing 89的C++代码

#include <bits/stdc++.h>
using namespace std;

typedef long long LL;

LL fastPow(LL a,LL b,LL p) {
    LL ans=1;
    while(b) {
        if(b & 1) ans=ans*a%p;
        a=a*a%p;
        b>>=1;
    }
    return ans%p; //not return ans
}

int main() {
    LL a,b,p;
    cin>>a>>b>>p;
    cout<<fastPow(a,b,p)<<endl;

    return 0;
}

/*
in:
3 2 7

out:
2
*/